Method of making an inflatable vulcanized article



Oct.. i9 1926.

R. HOPKRNSON METHOD 0F MAKING AN INPLATABLE VULCANIZED ARTICLE Filed June 5, 1925 2 Sheets-Sheet l Snom/woz RUSSELL HoPK/Nso/v 3313 hi@ @Mio/am @uw 1926 1,603,465A

R. lHOPKlNSON METHOD OF MAKING AN INFLATABLE VULCANIZED ARTICLE Filed June 5, 1925 v 2 Sheets-Sheet 2 Patented Oct. 19, 1926.

UNITED STATES PATENT OFFICE.

RUSSELL HOPKINSON, OF ELMHURST, NEW YORK, AS-SIGNOR T THE GOODYEARS INDIA RUBBER GLOVE MFG. COMPANY, 0F NA'UGATUCK, CONNECTICUT, COR- PORATION OF CONNECTICUT.

METHOD OF MAKING AN `INIliIiATABLE VULCANIZED ARTICLE.

I Application led June' 5, 192B. Serial No. 643,563.

This invention relates to a method of making an inflatable vulcanized article, more particularly as applied to the making of a pneumatic surf board. l

6 .The use of surf boards by bathers at the various beaches is becoming uite common. In using such boards the bat er walks out into the water as far as possible and upon the ap roach of a breaker launches himself l0 upon t e board and in the direction of the shore 'ust as the crest of the breaker reaches him, t e object bein to maintain the board in such a position t at it tends to slide by avity down the forward face of the wave,

l ut due to the inward movement of the wave.

the board is carried forward continually until the shore is reached. As'commonly constructed these boards are made of wood or other rigid material and their use is therefore attended with some risk, owing to the likelihood ofthe user and those in the vicinity bein struck by the board. Moreover, as the boar s are somewhat bulky they are incon. venient to carry when not in use. It has been proposed to make a pneumatic surf board 1n which the outer casing is divided into compartments and elongated infiatable bags inserted into the com artments, secured 1n place and then indivi ually iniated. Such boards are relatively heavy, expensive, and considerable time is requlred to assemble them.

An object is to provide a simple and economic method for making iniiatable rubber articles. v

A further object is to provide a method for making pneumatic surf boards and similar articles in the fiat without the use of forms.

For a detailed disclosure of the invention reference is had to the accompanying specication and drawings, in which latter:

Fig. 1 represents in sectional perspective a partially completed pneumatic article made according to one form of the method,

Fig. 2 is a similar view of the article in more or less diagrammatic form at a later stage in the carrying out of the method,

Fi 3 is a similar View of the finished inflate article,

Fig. 4 is a diagrammatic view illustrating a step in the carrying out of another modification of the method,

Fig. 5 illustrates a later stage of said modication,

Fig. 6 represents a finished article made by the method as shown in Figs. 4 and 5,

Figs. 7 and 8 are fragmentary illustrations of the artlcle in two stages of its manufacture by another form of the method,

Figs. 9, 10, 11, and 12 each illustrate articles made by further modifications of the method,

Fig. 13 is a plan view of a finished surf boar Fig. 14 is a side elevation thereof, and

Fig. 15 is a front View.

l Referrin to Figs. 1-3, when carrying out the metho in the manner shown therein, a bottom sheet 1 of any suitable unvulcanized rubberized fabric is laid in the flat, which sheet may be cemented on its upper face along its central portion and from thence to its left hand edge. A spacing strip of rubberized fabric 2 is then laid` on the central cemented portion and rolled down. Another strip1 3 of rubberized fabric of greater width is t en superposed on the strip 2 with its edges projecting at each side of the latter, and the projecting portion 4 which overlies the cemented ortion of the sheet 1 is rolled down into union with the latter. A strip 5 similar to the strip 3 is laid on the strip 3 in a shingled arrangement and that portion 6 of it which overhangs the cemented portion 85 of the sheet 1 is rolled into contact with the latter. A strip 7 similar to the strips 3 and 5 is next placed in position in the same manner and its overhangin portion 8 rolled down into connection with the sheet 1. If 90 the sheet 1 is of greater width this process will of course be continued until the edge of the sheet is reached. The strips 2, 3, 5, and 7 may be of fabric frictioned on its lower side ony, in which case the frictioned portions o the strips will not adhere to the uncoated fabric surfaces which they overlie. However, it may be desirable to friction both sides of the strips and in this case all portions of the strips which are not to be adhesively unitedmay be dusted with starch or talc. The right hand side of the sheet 1 may then be cemented4 and a series of strips joined thereto in the same manner but wlth the overlap oppositely directed. Those portions of the strips 'which are to be loo united to the sheet 1 may of course also be cemented. Each strip is then exactly doubled upon itself as shown diagrammatically in Fig. 2 and at the centerl a spacing strip 12 is laid on exactly above the spacing strip 2. A top sheet 13 which may have its under surface cemented is then united to the portions 9, 10 and l1 of the doubled over strips which overlie the respective portions 8, 6, and 4. and it is also united to the top spacing strip l2. By reason of the extended area of connection between the strips 3, 5, and 7, and the top and bottom said strips are vary strongly connected to the top and bottom. The top sheet 13 and bottom sheet 1 are then joined all around their edges in any suitable manner as by overlapping, and a valve inserted ata suitable place, which in the case of a pneumatic surf board may be inserted at the rear as shown at 14 in Fig. 13. The article may then be very lightobvious that the green rubber `to the bow and stern.

ly inflated to the form shown in Fig. 3 and cured. As the usual heat of vulcanization renders the stock so soft that it tends to run or become quite lastic it is preferable to use a stock containing one of the so-called cold cureaccelerators. When using such a stock the article may be lett to cure at ordinary temperatures, or if it is desired to hasten the process it may be heated for a short time at a relatively low temperature, for instance 150)F. lVhile in the present form of the invention the parts have been described as being cemented together it is arts may be merely adhesively united by roiling and the final cure relied on to permanently unite them in the manner commonl depended u on in making plied up rub er articles.`

oreover, if desired, the article may be built up of vulcanized stock with the use of an ordinary or a self curing cement to secure the parts.

In the case of some articles such as mattresses, cushions, etc., it may be desired to make them of the same thickness throughout, but in the case of the surf board it is preferred to have the greatest depth at a point between 1A and 1A, the length from the bow. and decrease the depth from this point To accomplish this purpose the strips 2, 3, 5, and 7 can be made of a width regularly decreasing, or the strips may be made of a uniform width and the portion of the strip which is cemented to the top or bottom made of increasing width from the point of greatest depth, or the two methods may be combined.

In a modified form of the method as illustrated in Figs. 4 to 6 the bottom and top sheets 15 and 17, respectively, are coated with cement to form adhesive spaced strips 16 correspondingly disposed on the" upper and lower sheets. Tubes 18 which may be formed of rubberized fabric are attened so as to form superposed plies, and the flattened tubes laid centrally on the cemented strips 16 of the bottom sheet and rolled down. The top` sheet 17 is then disposed so that its cemented strips 16 are located centrully of the to lies of the flattened tubes, the sheet rolledpdbwn and the edges of the sheets joined by lapping or otherwise to completely inclosc the article, which when intlated has the form shown in Fig. 6. In this modilication when it is desired to make the article ol greater depth at any point the tubes 18 may be made tapering or conical with the greatest diameter at the point where the greatest depth is desired, or instead the cemented area which joins each tube to the sheet may be made of a gradually increasing width from the point of greatest depth.

In Figs. 7 and 8 there is shown a further modilcation of the method which is ver similar to that shown in Figs. 1-3. In this form the bottom sheet 19 is laid flat as before and the spacing strip 20 is cemented to the bottom sheet as in the form shown in Fig. 1. l-lowever, the spacin strip is made of a greater width and its e ges are folded over as shown at 21. The stri s 22 are disposed on the bottom in shingle arrangement as in the vform shown in Fig. 1, but the stri s are of somewhat greater width and at t e edges are folded in as shown at 23. When the strips are doubled over the folded top edge 23 is disposed directly over the lower one. The central top spacing strip 24 is of a width corresponding to the bottom strip 20 and has its edges turned under as shown at 25. The top sheet 26 is then cemented and rolled down in exactly the same manner as in the form shown in Figs. 1-3. It will be seen from an ins ection of Fig. 8 that in the finished article t ie stri s 22 form strengthening and stilfening ri s exactly as do the strips 3, 5, and 7, but that in addition the portions of the ribs which are connected to the top and bottom also extend downwardly and upwardly, respectively, on the vertical portions of the ad]oining ribs, thereby both further strengthening the connection between the ribs and the top and bottom and also making the ribs stiffer. The extended ends of the central spacing strips 20 and 24 perform a similar function for the ribs adjoining them. In addition, in both the form shown in Figs. 1-3 and that shown in Figs. 7 and 8, the top and bottom are in effect made two ply by reason of the spacing strips and attaching ends of the connecting strips, thereby greatly strengthening the article.

A simplied form of the invention is shown in Fig. 9, in which the top and bottom sheets 27 and 28 are united along narrow spaced areas 29 by rolling them into adhesion or bv both rementing and rolling them so that in the finished and cured article while the remainder of the Contactin the top and bottom will be firmly united at these points. When inflated it assumes the shape as illustrated in the figure.

'lhe form shown in Fig. 10 is similar to that in Fig. 9 and the top and bottom sheets and 31, respectively, are united along narrow spaced areas 32 in the same manner as in the form shown in Fig. 9, but strengthening members suc-h as the stitches 33 are disposed in the joined areas, and the stitches covered by gum strips 34. It is obvious `that instead of' the stitches, staples or an other suitable faster'iings may be employe In the form shown in Fig. 11 the top sheet 35 and bottom sheet 36 are united along narrow spaced areas by means of the inter osed small tubes 37 of rubberized fabric. hese tubes are flattened out when the parts are rolled together and the superposed plies furnish a relatively extended uniting area to the top and bottom sheets. In the form shown in Fig. 12 the top sheet 38 and bottom sheet 39 are also united along narrow spaced areas by interposedv strengthening and stiflening members. Each stiflening member is formed of two superposed stri s 40 of rubberized fabric which may be ro led into adhesive contact on their center line and also stitched or otherwise secured along this line as shown at 41, l faces of the stri s 40 are kept from adhering by the use o starch or talc. In makin an article according to this modication o the method the bottom sheet is laid flat and a series of the strengthening members disposed on the bottom sheet in spaced relation, the bottom face of the lower strip 40 being cemented. 'Ihe strengthening members are then rolled down on the bottom sheet, the

upper face of the top strengthening member cemented, and the top sheet rolled down. rlhe edges of the top and bottom sheets are then joined as before and the article cured. This modification also provides an extended loining area between the strengthening memlier and the top and bottom sheets. It is obvious as before stated that either or both of' a pair of surfaces to be joined may be cemented or the natural adhesion may be relied upon while building up the parts.

It will lie seen that by my' invention a pneumatic surf board is provided which in the finished article is a unitary body, and which can be simply and economically built up in the flat from the prepared parts. By merely increasing the air pressure a surf board of' any desired stiffness may be obtained, but if desired stiflenin members may be inserted in the vertical ri s or in the top and bottom. By deflating the article it can be rolled into small compass for shipl ping or storage. When inflated the vertical ribs'3. 5, and 7 as s hown in Figs. 1 to 3, or the various connections shown in the modinecting members and also to stiffen the board.'`

lVhile the invention has been particularly shown and described as applied to a pneumatic surf board it is obvious that it is not so limited in its application and that it can be used for making pneuinatc floats of various kinds, mattresses, cushions, and many other articles, and it is therefore not desired to limit theinvention otherwise than as set forth in the appended claims.

Having thus described my invention, what I claim and ldesire to protect by Letters Patent is:

1. The method of making inflatable articles in the fiat which comprises joining a top and bottom of rubber containin r material in the flat by interposed strengthening elements disposed along spaced lines', 'and uniting all free edges of the top and bottom.

2. The method of making inflatable rubber articles which comprises superposing top and bottom sheets of rubber eontainin material, uniting them in the flat by the aiil of strengthening and connecting elements along a series of spaced lines, .and uniting their Jedges at all points to form an inflatable body. l

3. The method of making inflatable rubber articles which comprises superposing top and bottom sheets ofrubber containing material, adhesively uniting them in the flat by interposed strengthening and connectin elements dis osed along s aced lines, and unitin the s eet edges at all points to form an in atable body.

.4. The method of making inflatable rubber articles which comprises disposing in the flat a bottom sheet of rubber containing material, disposing a plurality of strengthening and connecting elements thereon and adhesively uniting a portion of each element to the sheet, superposing and uniting a to sheet in the flat to another portion of eac element in a similar manner, and uniting the edges of the sheets at all points to form an in atable bod 5. The method of making inflatable rubber articles which comprises disposing in the flat a bottom sheet of rubber containing material, disposing a plurality of strengthening and connecting elements in two ply relation on said sheet and adhesively uniting the lower ply of each element to the bottom sheet, superposin a top sheet and adhesively uniting it in the at to the upper pl of each element, and uniting the ed es of t e sheets at all points to form an in atable body.

6. The method of making inflatable rubber articles which comprises disposing in the flat a bottom sheet of unvulcanized rubber containing material, disposing a plurality of strengthening and connecting elements in two .ply relation on said sheet and adhesively uniting the lower ply of each element to the bottom sheet, similarly uniting the upper ply of each element to a top sheet in the flat, adhesively uniting the-edges of the sheets at all points, und curing by the aid ot' a non-halogen cold cure accelerator.

7. The method of making inflatable arti- -cles in the flat which comprises disposing a the flat a bottom sheet of rubber containing material, adhesively uniting thereto one edge ortion of each of a plurality of strengthenmg and connecting strips, said strips being arranged in two series with their i' ree edge portions oppositely directed, folding down said free edge portions over the united edge portions, adhesively uniting the upper surfaces of the free edge portions to a top sheet. and uniting the edges of the sheets at all points.

9. The method of making inflatable rub ber articles which comprises disposing in the flat a bottom sheet of rubber containing ma ferial, disposing thereon series of strengthening and connecting strips in oppositelyv directed and shingled arrangement, adhesively uniting to the sheet a portion of each strip in direct contact therewith, doubling each strip on itself, superposing a top sheet and adhesively uniting it to each strip at points directly above said first mentioned portions, and uniting the edges of the sheets at all points.

10. The method of making inflatable articles in the flat which comprises disposing a bottom ot' rubber containing material in the iat, adhesively uniting thereto a central spacing strip, disposing on said strip a connecting strip having an edge portion directly overlying said bottom at one side of the spacing strip, adhesively uniting said overlying edge yportion to the bottom, successively and similarly uniting a plurality of other connecting strips to said bottom, uniting a series of connecting strips to saidbottom in similar manner onthe opposite side of the spacing strip, folding over the free edge portion of each connecting strip on its adhesively united edge portion, disposing a second spacing strip above said first one, ad hesively uniting a top to said free edge portions and second spacing stri in manner similar to the bottom, and uniting the top and bottom at their free edges to form an infiatable body.

Signed at. New York city, county of New York, and State of New York, this 1st day of June, 1923.

RUSSELL HOPKINSON. 

